The present invention relates to on-chip magnetic devices, and more specifically, to systems and methods for laminating magnetic cores for on-chip magnetic devices such as inductors and transformers.
On-chip magnetic inductors/transformers are important passive elements with applications in the fields such as on-chip power converters and radio frequency (RF) integrated circuits. In order to achieve high energy density, magnetic core materials with thickness ranging several 100 nm to a few microns are often implemented. Ferrite materials that often used in bulk inductors have to be processed at high temperature (>800° C.), which is incompatible with complementary metal-oxide-semiconductor (CMOS) processing. Thus, a majority of magnetic materials integrated on-chip are magnetic metals such as nickel iron (Ni—Fe), cobalt iron (Co—Fe), cobalt zirconium titanium (Co—Zr—Ti) and the like. Magnetic metals can be deposited through vacuum deposition technologies (i.e., sputtering) or electrodepositing through an aqueous solution. Vacuum methods have the ability to deposit a large variety of magnetic materials and to easily produce laminated structures. However, they usually have low deposition rates, poor conformal coverage, and the derived magnetic films are difficult to pattern. Electroplating has been a standard technique for the deposition of thick metal films due to its high deposition rate, conformal coverage and low cost.